<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 500px;
            height: 500px;
            border: 3px solid skyblue;
            margin: 0 auto;
            background: url(吨吨.jpg) no-repeat;
            background-size: cover;
        }
    </style>
</head>

<body>
    <div>

    </div>
</body>

</html>